Using Northern and Southern blot techniques, you study a gene, CAE1, that seems to be associated with lung cancer. Your probe in both blots is a 32P-labeled single strand DNA that can base pair with the CAE1 RNA and with the CAE1 gene.
You isolate DNA and RNA from brain, heart, lung, and cancerous lung tissue. The DNAwas cut into DNA fragments with a restriction endonuclease before electrophoresis. The results of the blots are shown here.
Which one of the following is an observation or conclusion consistent with the data?
A. There are fewer CAE1 genes in brain tissue compared to heart tissue.
B. The DNA sequence of the CAE1 gene in lung cancer cells is different than in other tissues.
C. The amount of CAE1 RNA in lung cancer cells is higher than in other tissues.
D. The amounts of all RNAs in heart cells and normal lung cells are the same.
E. Deleting the CAE1 gene in all tissue types would be a possible cancer cure with little or no side effects.
Which of the following is nota cellular response to amino acid starvation in E. coli?
A. Levels of guanine tetraphosphate rise.
B. Levels of cAMP decrease.
C. The transcription of genes needed for rapid growth decreases.
D. rRNA synthesis is decreased.
Which of the following is true of the structure of typical transcriptional activators?
A. They contain only one type of motif.
B. The regulatory domain contains the DNA-binding motif.
C. The DNA-binding domain always binds to the coactivator.
D. They contain a regulatory domain that can be functional when separated from the DNA-binding domain.
Differential RNA processing may result in:
A. a shift in the ratio of mRNA produced from two adjacent genes.
B. inversion of certain exons in the mature mRNA.
C. the production of the same protein from two different genes.
D. the production of two proteins with different activities from a single gene.
Which of the following is not true of mitotic recombination?
A. Recombination occurs during mitosis when replication forks encounter lesions in the process of repair or single-strand breaks.
B. The recombinase Dmc1 is active in mitotic and meiotic recombination mechanisms.
C. The BRCA2 protein is a recombination mediator active in mitotic recombination repair.
D. It employs synthesis-dependent strand annealing (SDSA) most commonly.
E. It can employ double-strand break repair (DSBR), which can lead to crossing over.
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